0:02 in this video we're going to go over how
0:05 to do inequalities on the ged
0:07 and they could give you word problems
0:09 like this
0:11 algebraic ones like this
0:14 or number line ones like this
0:16 so we'll go over all of them
0:18 now the first one your wedding food
0:20 budget is 14.50
0:22 but let's pause there
0:26 look at the end we notice we have 14.50
0:28 we're either gonna stay above or below
0:30 that amount here
0:33 so let's break down these symbols
0:35 when it goes in this direction that
0:38 means more than or greater than
0:40 and then this one less than
0:42 and you could remember it because you
0:44 could turn the top one into a g the
0:46 bottom one and now
0:48 okay but this statement saying we're
0:51 going to spend this looks like an l less
0:53 than 1450
0:55 and that's what we want because we want
0:58 to stay under our budget so that one is good
0:59 good
1:01 the next one would say we're going to
1:04 spend greater than 1450 but that's no good
1:05 good
1:08 so as you could see a and c those might
1:11 be it b and d they're out
1:13 the next thing we want to find is what
1:15 are we going to do with x
1:17 that's the number of people
1:20 are we going to multiply it by 28 or by 500
1:21 500 but
1:22 but
1:25 the meals are 28 per person
1:28 we have x number of people
1:31 so we want to multiply 28 times x
1:34 so it's gonna have to be that first one a
1:35 a
1:37 because the caterer we just pay that one time
1:38 time
1:42 so we just add that into the mix there
1:44 okay not too bad but let's check out
1:47 another one
1:49 now let's jump to the end here because
1:52 we want to earn more than 500 this week
1:54 so let's look at these symbols
1:56 well the first one this looks like an l
1:59 less than 500 no good
2:02 but this one greater than more than 500
2:04 that's great let's keep that and same
2:06 thing on the bottom
2:09 okay get rid of a and c
2:11 now the question is what are we going to
2:13 multiply 30 by
2:15 well we could either do it by this or this
2:16 this
2:19 but 30 represents the number of hours
2:22 we earn 12 dollars per hour
2:25 so therefore those are the two we want
2:27 to multiply
2:30 because b would say okay we work 30
2:34 hours but we only make 12 cents per hour
2:37 but that's no good so it's got to be d
2:39 that last one there
2:42 and then finally our sales is x
2:45 and we're going to get 12 of that amount
2:47 so that's why we multiply it by point 12.
2:48 12.
2:51 same thing as 12
2:53 okay one other one
2:55 now in this case the answers are all
2:57 just one number
2:58 when that happens they've actually
3:01 solved the inequality so let's go ahead
3:02 and grab that
3:05 now if you've solved equations before
3:07 it's the exact same process but if not
3:09 no worries
3:12 the goal is to get x all by itself
3:14 but to do that we don't want that
3:17 fourteen thousand five hundred
3:18 so the first thing we're going to do is
3:20 subtract that
3:22 whatever you do to one side of the
3:24 problem it gets split right there you're
3:26 going to go ahead and do it to the right
3:28 side as well
3:31 and then that'll cancel these guys
3:34 drop down the negative 32x
3:38 then 100 minus 14 500 that'll give us that
3:39 that
3:41 whatever is in front of x is being
3:43 multiplied by x
3:46 we want to do the opposite
3:48 opposite of multiplication
3:51 divide by negative 32
3:54 and we'll do it to both sides there
3:56 okay those will cancel
3:57 and then
3:59 whatever this turns into this division
4:02 is going to give us the answer
4:04 however there's one other important aspect
4:05 aspect
4:07 when you divide by a negative with inequalities
4:09 inequalities
4:11 it's going to flip this
4:12 because this is a greater than it's
4:14 going to go ahead and flip it to a less than
4:16 than
4:17 but let's go ahead and do this with the
4:22 calculator let's do negative 14 400
4:25 divided by negative 32 450
4:26 450
4:29 so therefore x less than or equal to 450.
4:31 450.
4:34 now x in this case represents miles
4:36 we're driving on a full tank of gas
4:38 we're seeing how far we could go
4:40 so the number of miles is going to be
4:44 less than or equal to 450
4:50 okay let's just look at the algebraic
4:52 ones now
4:54 same idea as what we were just doing on
4:57 the previous problem let's check it
4:59 now when you solve an equation it just
5:01 has an equal sign when you solve an
5:04 inequality it's got a greater than or
5:05 less than
5:08 but it's still the same method for both
5:10 of these
5:12 okay so same thing we want to get x by
5:15 itself but we have a minus six
5:18 let's get rid of it let's add six
5:21 and then same thing on the other side
5:22 let's do it
5:25 these will cancel but let's break out
5:26 the calculator
5:29 because now we've got four thirds
5:31 you could use that fraction button right
5:33 there n over d
5:36 and then plus six
5:39 okay 22 over 3.
5:41 so that's on the right side and then
5:44 this one just drops straight down
5:45 but once again when you have something
5:48 in front of x that's multiplied by x
5:50 we want to get rid of it so we want to
5:52 do the opposite we're going to divide
5:55 both sides by two-thirds
5:57 that'll get rid of these
5:59 and then let's do it with the calculator here
6:00 here
6:03 we'll start off with 22 over three this
6:05 calculator is amazing same one you use
6:07 on the ged
6:10 but then divided by another fraction two
6:12 over three
6:14 ba boom eleven
6:15 eleven
6:17 kinda surprising but the fractions cancel
6:19 cancel
6:21 it's a positive so we don't flip the
6:24 sign we just keep it a greater than and
6:25 that's it
6:28 so final answer x is greater than or
6:31 equal to 11.
6:33 okay let's do one last version of this
6:35 with parentheses
6:37 because in this case you always want to
6:40 start with distribution
6:41 in other words you're going to go ahead
6:44 and multiply that thing in front times 8
6:46 so let's do that
6:48 okay our fraction we could go ahead and
6:51 do negative three
6:53 down two
6:58 negative twelve
7:00 so let's bring down the left the less
7:03 than or equal to negative 12 and then
7:06 just tack on the y right there
7:07 now we're going to multiply negative
7:10 three halves times twenty let's do it we
7:12 could start off with the negative this
7:15 time three down two
7:17 times 20
7:20 negative 30 so we'll put it as a minus
7:21 30 there
7:23 but once again we want to get y by
7:26 itself we want to get rid of that minus
7:29 30. we'll do the opposite we'll add 30
7:31 to both sides
7:33 that'll get rid of them there
7:36 the left side that turns into 42
7:39 and then negative 12y right there
7:40 but you know what to do they're next to
7:43 each other so as you've seen the last
7:45 step is always division
7:48 divide both sides by negative 12.
7:50 those will cancel
7:51 but don't forget
7:54 you just divided by a negative so we're
7:57 gonna have to flip the sign
8:00 okay 42 divided by negative 12 that'll
8:03 get us negative 3.5
8:06 goes from a less than or equal to to a
8:08 greater than or equal to
8:10 and we're home free
8:12 unfortunately it's not the same as one
8:14 of these just yet
8:17 so imagine that this is a little pac-man
8:18 and this is its mouth
8:22 so it's eating negative 3.5 it always
8:23 eats the bigger number
8:27 which of these is doing the same thing
8:30 well that first one that pac-man is also
8:32 eating negative 3.5
8:36 so it's the same thing as a there
8:39 now students often wonder and ask why
8:41 does dividing by a negative flip the sign
8:42 sign
8:45 let's look at an example real quick
8:47 okay 4 is greater than 2
8:49 no surprise
8:50 but let's divide both sides by a negative
8:52 negative
8:55 4 divided by negative two negative two
8:59 two divided by negative two negative one
9:02 however when you look at a number line
9:03 whatever is further to the right is bigger
9:05 bigger
9:08 so surprisingly negative one is bigger
9:10 than negative two
9:12 in other words we went from a greater than
9:13 than
9:15 to a less than
9:17 and that's why it flips because when you
9:19 go into the negatives then it's backwards
9:20 backwards
9:23 whatever is actually a smaller negative
9:26 is technically bigger
9:29 and one last type here
9:32 okay which represents this
9:34 okay x is greater than or equal to
9:36 negative 1.5
9:38 one thing you could look at is this
9:40 equal sign
9:42 means that the hole is going to be
9:43 filled in
9:46 so could be c could be d let's get rid
9:48 of a and b
9:50 and then we know we say it is greater
9:53 than so it's going to be to the right
9:56 so it's going to have to be c
9:58 one of the ways my students remember it
10:00 is this looks like an arrow pointing to
10:01 the right
10:03 so you want the arrow also to point to
10:05 the right
10:06 and then the other ones if you're
10:09 curious or these ones
10:11 just keep in mind when it's greater than
10:13 it's going to be to the right
10:15 and what's nice is less than is to the
10:19 left so l and l
10:21 okay these are the main types of
10:24 inequalities that show up on the ged
10:26 let me know what questions and issues
10:29 you run into you got these we'll see in
10:30 the next video toodles